Power supply voltage is often determined after integrated circuit processing is complete. Voltage is tuned to optimize power and performance. Increasing voltage reduces delay, increases performance, but also increases power. There are many circuits, such as pulse generators and dynamic circuits, where some delay dependence on voltage is desired, but the circuits lose functionality if some delays in critical paths are reduced too far. These delays can cause an otherwise good chip to be discarded because the chip does not meet power, performance, and functionality specifications.